Question

A velocity selector has an electric field of magnitude 2830
N/C,directed vertically upward, and a horizontal magnetic field
that isdirected south. Charged particles, traveling east at a speed
of6.73 x 103 m/s, enter the velocity selector and are
ableto pass completely through without being deflected. When
adifferent particle with an electric charge of +4.90
x10-12 C enters the velocity selector traveling east,
thenet force (due to the electric and magnetic fields) acting on it
is1.94 x 10-9 N, pointing directly upward. What is
thespeed of this particle?